The present disclosure relates to data channels and more particularly those that utilize soft output viterbi algorithms (SOVA).
In communication channels, data must be transmitted through the channel reliably. Data is represented as a sequence of bits, which each bit taking a value of zero or one. In most communication channels, two major components ensure the reliability of the data: a detection channel (or detector) and an error correction code (ECC). The detector receives an analog waveform from the channel, converts the analog waveform to a digital waveform, and then converts the digital waveform into ones and zeros. The ones and zeros are grouped in a contiguous subsequence of bits known as symbol. The number of bits in a symbol is determined as a parameter of the ECC and is typically a small number, such as ten. The data symbols are transmitted to an ECC decoder, where erroneous symbols are corrected, assuming that the number of symbols that the ECC has been designed to correct has not been exceeded.
In some instances, the detector utilizes an algorithm such as a SOVA in identifying reliability data to the analog waveform information that is received. This reliability information is known as “soft” information and can be processed to determine signals sent in the analog waveform. A trellis can be traversed using the SOVA and calculations for traversing various paths can be made to determine a most likely path.